Low bone mineral density (BMD) is correlated with Alzheimer's disease and its severity, but the association remains unclear in adults (≥50 years) without a history of stroke or dementia.We assessed BMD and cognitive function using the Mini-Mental Status Examination (MMSE) in 650 stroke- and dementia-free subjects (≥50 years) who were recruited for an early health check-up program between January 2009 and December 2010.The mean age was 62.9 ± 8.0 years and mean MMSE score was 27.6 ± 3.6. A total of 361 subjects had reduced BMD: 197 (30.3%) had osteopenia and 154 (23.6%) had osteoporosis, based on criteria of world health organization. A total of 5.4% of the male subjects had osteoporosis, versus 19.8% of the female subjects. After adjusting for age, sex, education, and other possible confounding factors such as hypertension, diabetes mellitus, and smoking, the estimated odds ratio for cognitive impairment was 1.72 for the osteopenia group (95% confidence interval [CI] 1.09-2.14, P = .019) and 2.81 for the osteoporosis group (95% CI 1.78-4.45, P < .001).Low BMD is correlated with cognitive impairment in community-dwelling adults aged 50 years and above without any medical history of stroke or dementia, especially in women. A community-based, early life, preventive osteoporosis education campaign might decrease the incidence of dementia.